Friday August 14, 2026
Phys —
Why do two individuals faced with the same information sometimes make completely different decisions? It is a question made famous by Nobel laureate Daniel Kahneman, whose book “Thinking, Fast and Slow” explored the contrast between rapid, intuitive decisions and slower, more deliberative thinking in humans.
Now researchers studying wild fish in Lake Tanganyika have found a striking parallel. In more than 5,000 underwater trials, researchers from the Max Planck Institute of Animal Behavior, Université Clermont Auvergne and the French National Center for Scientific Research tested the decision-making of two closely related species of featherfin cichlids.
When decisions were simple, the fish behaved identically. But when choices became more complex, one species made rapid, decisive choices while the other slowed down and appeared to integrate several pieces of information before deciding.
The findings, published in the journal Proceedings of the National Academy of Sciences, suggest that evolution or life history can alter not just what animals choose, but how they make decisions.